Submersible, screenless, non-clog pump units. For the pumping of liquids containing solids. Unscreened sewage-wastes-paper pulp-food solids-industrial by-products-beet pulp-stormwater-tannery wastes. Motor is sealed to run completely under water and is furnished with stainless steel shaft, double mechanical shaft seals housed in filled chamber. Motor in addition to overload protection, is also furnished with a built-in moisture detection device. This protective unit immediately detects presence of moisture in the seal housing indicating leakage at the bottom seal, requiring a relatively inexpensive repair since the upper seal has prevented the entrance of water into the motor housing itself. Capacities 50 to 2000 GPM.